Test out the codspeed walltime instrument (dedicated hardware benchmarks for IO)

[Cadair]

The major drawback with codspeed has been we can't test the I/O because syscalls are excluded, this is now not the case if you use the codspeed macro runners: https://docs.codspeed.io/instruments/walltime

We get 120 mins/month free (which probably isn't enough) but we could be smart what and when we run with that runner. Also we could pay for more minutes.